Improve handling of incomplete files in web UI
Part of #667 (closed). Specifically:
-
Make the file views return a simple 404 if FileInArtifact.complete
is false, rather than logging a noisy traceback -
Don't link to incomplete files in the artifact detail view; they should still be listed, but without a link and followed by "(incomplete)" -
Mark artifacts as incomplete in artifact lists (particularly the work request detail view) if any of their files are incomplete